That rumbling sound you hear isn’t a snow-removal truck, a low-flying plane or a train inadvertently chugging through your backyard.

No, it’s the low, slow churning of civic discontent, fomenting thanks to the decades-long trend toward educational mediocrity and resulting in a grass-roots movement that will — with any luck at all — restore our nation’s status as a well-educated and virtuous people.

You could call it “Occupy Parental Authority Over Indoctrination and Educational Malpractice Being Perpetrated by the Liberal Educational Establishment.” In fact, that has a nice ring to it.

As with the Occupy movement, the goals of this revolution are varied. (Unlike the Occupy movement, this uprising seeks more freedom, not government serfdom, but I digress.)

Some folks in this movement are protesting the left-wing socialist propaganda that passes in our public school classrooms for history, social studies, economics and literature curricula.

Others are focused on protecting their children’s innocence and instilling their moral and religious values by resisting the so-called comprehensive sexuality agenda and its full-on mandate to normalize homosexuality and transgenderism, regardless of the religious beliefs of public school students.

A few really radical parents actually are protesting — by way of engaging with their local school boards — the watered-down math and science programs that result in abysmal test scores and uneducated graduates.

Sheesh. Talk about nerve!

Yet rather than camp out in city parks for months of pointless demonstrations, the people behind these new, local uprisings are taking constructive action, school by school, city by city, and even in the halls of their state capitols.

Just a few weeks ago in New Hampshire, the legislature put in place (by overriding a gubernatorial veto) a law that lets parents provide alternative curricula to material being presented in their children’s classrooms that such parents find offensive or contrary to their moral or religious beliefs.

Now, the New Hampshire legislature is attempting to create a school choice alternative — including for private schools — by initiating an education credit against the business profits tax. The goal of this law is to “allow maximum freedom to parents and independent schools to respond to and, without governmental control, provide for the educational needs of children, and this act shall be liberally construed to achieve that purpose.”

It’s almost as if the New Hampshire legislature respects the authority of parents to make decisions about the education of their minor children. Weird, right?

In New York City, an organization called the NYC Parents’ Choice Coalition is gathering petition signatures in favor of abstinence-centered sex education rather than the graphic and offensive comprehensive sexuality program launched in the fall. While the coalition says it shares the programmatic goals of reducing teen pregnancy and sexually transmitted diseases, parents want the emphasis on abstinence and not the program’s Planned Parenthood-approved agenda.

The language of the parents’ petition reveals just how radical they are: “We, and many other parents, would prefer an alternative program which focuses on abstinence as the healthiest choice and encourages children to wait at least until they are adults before becoming sexually active. We will be opting our children out of all sex education classes until an alternative evidence-based program in line with common sense and our personal beliefs is allowed under the mandate.”

And in Tampa, Fla., civic groups are organizing to demand that Hillsborough County Schools deny CAIR — the Council on American Islamic Relations — or other groups with ties to terrorism access to children through classroom presentations. Though CAIR is a federally designated Hamas entity, apparently that doesn’t keep it from offering presentations to schoolchildren under the banner of multiculturalism and diversity.

As it happens, this is National School Choice Week in America, and parents are speaking out for alternatives to the public education system that restore common sense and educational excellence in their children’s classrooms.

This is one time when parents rightly ought to raise their voices and make themselves heard.

Marybeth Hicks is a columnist for The Washington Times and founder and editor of Ontheculture.com.